1. Field of the Invention
The present invention relates to a method of operating a flying shear which has at least one drum provided with a blade. The method comprises synchronizing the peripheral speed of the blade with the feed rate of rolled strip.
2. Description of the Related Art
Such synchronized shears are known, for example, from DE 196 37 862 A1 as high-speed shears for cutting rolling strip to length. In this connection, two oppositely positioned drums which can be advanced toward one another are used which are both provided with blades, or only one of the drums is provided with an anvil or is used as an anvil.
The advancing strokes are dimensioned such that the two blades of two oppositely positioned drums overlap at a minimal distance or the shearing edge of one blade rests under pressure against the anvil of the oppositely positioned drum or its periphery. However, it was found that for such shearing processes the wear of the blades and of the anvil surfaces, if employed, is undesirably high, and it was found that the manufacture of the shears must be realized within the most narrow tolerances—a factor increasing manufacturing costs—for achieving an exact placing of the blades onto a anvil or for a defined cut with two blades in order to ensure perfect cutting efficiency.
GB 2 203 677 A discloses already a shearing device comprising a blade and an anvil which are adjusted relative to one another such that the strip to be cut is only scored. By a later application of tensile force onto the strip, tearing occurs at the scored areas resulting in a separation of the strip. In these shearing devices, an anvil drum, which must be synchronized in a complex way, is required in addition to the blade drum. Moreover, contacting of the strip with the anvil drum can cause damage to the strip.